This invention relates to a refrigerant system that may be utilized for operation in both a heating and cooling modes, and wherein an economizer cycle is provided in both modes.
Refrigerant systems provide cooled air in an air conditioning mode and a heated air in a heat pump mode. Essentially, the refrigerant flow through the system is reversed to provide the two distinct modes.
One modem development in refrigerant cycles is the inclusion of an economizer cycle. An economizer cycle taps a portion of a refrigerant flow downstream of the outdoor heat exchanger in the cooling mode or downstream of the indoor heat exchanger in the heating mode. The tapped refrigerant is used to subcool the main refrigerant flow. The tapped refrigerant passes through an economizer expansion device, where its temperature is reduced during the expansion process, and then through an economizer heat exchanger.
The subject of this invention is to combine a four-way reversing valve with a main expansion device in a refrigerant cycle that will preferably have a different size orifice to the refrigerant flow in cooling and heating modes. Having stand alone expansion devices may be undesirably expensive, as well as presents additional reliability concerns.